Terms & conditions

1. Acceptance of these terms

By accessing or using digitalverniercaliper.com ("the site") you agree to these terms and conditions. If you do not agree with them, please do not use the site. Where you use the site on behalf of a school, university or employer, you confirm you have authority to accept these terms on that organisation's behalf.

2. Who provides this site

The site is operated by an individual, not a company, as a free educational resource. It is provided at no charge, with no account, no subscription and no payment of any kind. Nothing on the site is offered for sale, and no contract for goods or services arises from using it.

3. Permitted use

You may use the site freely for learning, teaching, revision and reference. In particular, and without needing to ask permission, you may:

• — use the simulator in lessons, lectures, laboratory sessions and tutoring;
• — link to any page on the site from a course page, worksheet or handout;
• — display the simulator on a projector or shared classroom screen;
• — quote short passages from the written guides with attribution and a link back to the page quoted.

You may not:

• — copy the site, or substantial parts of its text, code or graphics, and republish it elsewhere as your own;
• — charge others for access to the site or present it as a paid product of your own;
• — attempt to interfere with the site's operation, gain unauthorised access to any system behind it, or place automated load on it beyond ordinary browsing;
• — remove, obscure or alter any attribution, notice or branding, including by embedding the site in a frame that hides its origin;
• — use the site for anything unlawful, or in breach of any applicable regulation.

4. Accuracy and educational purpose

This is the most important term on the page, and the one most specific to what this site is.

The caliper shown on screen is a simulation. It is drawn by your browser at a scale determined by your device, your display and your zoom level. The optional calibration control improves that approximation but cannot make it exact, because a web browser has no reliable way to determine the true physical size of your screen.

The simulator and the written guides are provided for education and practice only. They are not a substitute for a calibrated instrument, for professional training, or for the procedures and standards that apply in your context. You must not rely on this site for engineering, manufacturing, quality assurance, construction, medical, laboratory, safety or legal purposes, or for any decision where an incorrect measurement could cause loss, injury or damage.

The guides are written and checked with care, and references to standards such as ISO, ASME, BS and DIN are given for orientation. Standards are revised, however, and summaries are not the standards themselves. Where accuracy matters, consult the current published standard and a qualified person. No warranty is given that any content is complete, current or free from error, and content may be corrected or changed at any time.

5. Availability

The site is provided on an "as is" and "as available" basis. It may be unavailable, interrupted or withdrawn at any time, with or without notice, including for maintenance or for reasons outside our control. No guarantee of uptime is given, and you should not build a lesson, examination or assessment around the assumption that the site will be reachable at a particular moment.

The simulator continues to work in an already-open browser tab if your connection drops, but that behaviour is a convenience, not a commitment.

6. Intellectual property

The text of the guides, the design of the site, the simulator's interface and the vector drawings of the instrument are the property of the site's operator and are protected by copyright, except where third-party material is used under its own licence. The site name and logo are used as identifiers of this site.

The vernier principle itself, the formulae, and the physical design of measuring instruments are of course not owned by anyone here — only this particular expression of them is. The permissions in section 3 are given in addition to whatever fair dealing, fair use or equivalent rights already apply to you by law; nothing here narrows those.

7. Third-party links and services

The site may link to external pages and relies on third-party services — a hosting provider and a web font service — to deliver its pages, as described in the privacy policy. We do not control those sites or services and are not responsible for their content, availability or practices. A link is not an endorsement.

If advertising is introduced in future, adverts and their content are supplied by the ad network, not by us. We do not endorse advertised products and are not party to any transaction between you and an advertiser.

8. Privacy

Use of the site is also governed by the privacy policy, which forms part of these terms. In short: the site has no accounts, sets no cookies of its own, and keeps only two preferences in your browser's local storage.

9. Disclaimer and limitation of liability

To the fullest extent permitted by law, the site is provided without warranties of any kind, whether express or implied, including any implied warranties of merchantability, fitness for a particular purpose, accuracy or non-infringement.

To the fullest extent permitted by law, the site's operator shall not be liable for any loss or damage — including indirect or consequential loss, loss of profit, loss of data, or loss arising from a measurement, calculation or decision made in reliance on this site — arising out of your use of, or inability to use, the site.

Nothing in these terms excludes or limits liability for death or personal injury caused by negligence, for fraud or fraudulent misrepresentation, or for any other liability that cannot lawfully be excluded. If you are a consumer, these terms do not affect your statutory rights.

Because the site is provided free of charge, no fee has been paid against which a proportionate cap could be measured; your remedy, should you be dissatisfied with the site for any reason, is to stop using it.

10. Changes to the site and these terms

The site is developed continuously: features may be added, altered or removed, and content may be rewritten or corrected at any time without notice. These terms may also be revised; the date at the top of the page shows when they were last changed, and continuing to use the site after a revision means you accept the revised terms.

11. Governing law

These terms are governed by the laws of the operator's country of residence, and any dispute arising from them is subject to the exclusive jurisdiction of its courts. If you are a consumer resident elsewhere, this does not deprive you of the protection of mandatory consumer-protection rules of the country in which you live.

If any provision of these terms is found to be unenforceable, the remaining provisions continue in full effect.

12. Contact

Questions about these terms, permission requests that go beyond section 3, and copyright notices should be sent to hello@digitalverniercaliper.com. See the contact page for more.